In the first year of this pilot study we successfully initiated a prospective study of growth and growth factors in pediatric patients. The preliminary findings are exciting because of two major findings. The first is that during illnesses which have been shown to alter insulin- like growth factors (IGF) and induce proteolysis of insulin-like binding proteins (IGFBP), acid labile substance (ALS) and IGFBP-2 levels are not altered. These growth factors may be the best serum factors to evaluate growth hormone (GH) production. The relationship of these growth factors and primed provocative GH testing during illness will be of extreme interest. Such studies are planned for the beginning of the year after diagnosis. Several patients are approaching that anniversary. The second is that the poor growth immediately following cancer diagnosis and treatment is not due to GHD and may not be due to IGF-1 or IGFBP-3 deficiency. The second year studies should further validate these preliminary results.